The present invention relates to blends of polyvinyl chloride resins with copolymers of vinyl aromatic compounds such as styrene, vinyltoluene, or chlorostyrene.
The blending of polyvinyl chloride resins with other polymeric materials has heretofore been suggested for the purpose of altering the properties of a polyvinyl chloride resin to suit particular applications. Such blends are described, for example, in U.S. Pat. No. 3,626,033 which teaches the formation of blends of polyvinyl chloride, a polydiene rubber nitrile graft copolymer, and a styrene-maleic anhydride copolymer containing 15-30 weight percent of maleic anhydride; and U.S. Pat. No. 3,882,192 which teaches the formation of blends containing a polycarbonate, a vinyl chloride polymer, and an ABS graft polymer, styrene/maleic anhydride copolymer or an ethylene/vinyl acetate copolymer.